#include<stdio.h>
#include<assert.h>
char* my_strcpy(char* dest, const char* src)
{
	assert(dest && src);
	char* ret = dest;
	while (*src != '\0')
	{
		*dest++ = *src++;
	}
	*dest = *src;
	return ret;
}

int main()
{
	char *s1 = "Hello,World";
	char s2[20] = { 0 };
	my_strcpy(s2, s1);
	printf("%s", s2);
	return 0;
}